"Precious" is often used for cute now, or for a better way to say spoiled, but I think it's means much more something that can't be replaced, that we value greatly, and without which we would be far less than we are. There is the preciousness of human striving, for example, art and thought and ideas. Each individual is precious because that individual brings something that no one else can to the fabric of our conciousness. And, ironically, precious things are now precious (rare) in our world. That is, they may be endangered. The preciousness of existence needs to be protected.